Genetic Considerations

Pheochromocytoma occurs as a feature of several heritable syndromes including neurofibro-matosis I, von Hippel-Lindau syndrome, tuberous sclerosis and MEN (MEN Ila—medullary thyroid cancers, pheochromocytoma, parathyroid tumors, and neuromas). MEN II is a cancer syndrome that has an autosomal dominant transmission pattern. Pheochromocytoma may be seen in about half the persons in families with MEN-IIA, and in some of these families, pheochromocytoma can cause up to 30% of deaths. Individuals with MEN II have mutations in the RET proto-oncogene. Familial pheochromocytoma is associated with mutations in the suc-cinate dehydrogenase complex.